.TH IRB 1 "Ruby Programmers Reference Guide" "November 7, 2012" "UNIX"
.SH NAME
\fBirb\fP
\- Interactive Ruby Shell
.SH SYNOPSIS
.br
\fBirb\fP
[\fB\--version\fP]
[\fB\-dfm\fP]
[\fB\-I\fP \fIdirectory\fP]
[\fB\-r\fP \fIlibrary\fP]
[\fB\--\fP[no]inspect]
[\fB\--\fP[no]readline]
[\fB\--prompt\fP \fImode\fP]
[\fB\--prompt-mode\fP \fImode\fP]
[\fB\--inf-ruby-mode\fP]
[\fB\--simple-prompt\fP]
[\fB\--noprompt\fP]
[\fB\--tracer\fP]
[\fB\--back-trace-limit\fP \fIn\fP]
[\fB\--irb_debug\fP \fIn\fP]
[\fB\--\fP]
[program_file]
[argument ...]

.SH DESCRIPTION
\fBirb\fP
is the REPL(read-eval-print loop) environment for Ruby programs.

.SH OPTIONS

.TP
\fB\--version\fP
Prints the version of
\fB.\fP

.TP
\fB\-E\fP \fIexternal\fP[]:\fIinternal\fP
.TP
\fB\--encoding\fP \fIexternal\fP[]:\fIinternal\fP
Same as `ruby -E' .
Specifies the default value(s) for external encodings and internal encoding. Values should be separated with colon (:).

You can omit the one for internal encodings, then the value
("Encoding.default_internal") will be nil.

.TP
\fB\-I\fP \fIpath\fP
Same as `ruby -I' .
Specifies
$LOAD_PATH
directory

.TP
\fB\-U\fP
Same as `ruby -U' .
Sets the default value for internal encodings
("Encoding.default_internal") to UTF-8.

.TP
\fB\-d\fP
Same as `ruby -d' .
Sets
$DEBUG
to true.

.TP
\fB\-f\fP
Suppresses read of
\fI~/.irbrc\fP.

.TP
\fB\-h\fP
.TP
\fB\--help\fP
Prints a summary of the options.

.TP
\fB\-m\fP
Bc mode (load mathn, fraction or matrix are available)

.TP
\fB\-r\fP \fIlibrary\fP
Same as `ruby -r'.
Causes irb to load the library using require.

.TP
\fB\--inspect\fP
Uses `inspect' for output (default except for bc mode)

.TP
\fB\--noinspect\fP
Doesn't use inspect for output

.TP
\fB\--readline\fP
Uses Readline extension module.

.TP
\fB\--noreadline\fP
Doesn't use Readline extension module.

.TP
\fB\--prompt\fP \fImode\fP
.TP
\fB\--prompt-mode\fP \fImode\fP
Switch prompt mode. Pre-defined prompt modes are
`default', `simple', `xmp' and `inf-ruby'.

.TP
\fB\--inf-ruby-mode\fP
Uses prompt appropriate for inf-ruby-mode on emacs.
Suppresses --readline.

.TP
\fB\--simple-prompt\fP
Makes prompts simple.

.TP
\fB\--noprompt\fP
No prompt mode.

.TP
\fB\--tracer\fP
Displays trace for each execution of commands.

.TP
\fB\--back-trace-limit\fP \fIn\fP
Displays backtrace top
\fIn\fP
and tail
\fIn\fP.
The default value is 16.

.TP
\fB\--irb_debug\fP \fIn\fP
Sets internal debug level to n (not for popular use)


.SH ENVIRONMENT
.TP
.B IRBRC


Also
\fBirb\fP
depends on same variables as
\fBruby\fP(1).

.SH FILES
.TP
.B ~/.irbrc
Personal irb initialization.


.SH EXAMPLES
.nf
\&  % irb
.fi
.nf
\&  irb(main):001:0> \fB1 + 1\fP
.fi
.nf
\&  2
.fi
.nf
\&  irb(main):002:0> \fBdef t(x)\fP
.fi
.nf
\&  irb(main):003:1> \fBx+1\fP
.fi
.nf
\&  irb(main):004:1> \fBend\fP
.fi
.nf
\&  => nil
.fi
.nf
\&  irb(main):005:0> \fBt(3)\fP
.fi
.nf
\&  => 4
.fi
.nf
\&  irb(main):006:0> \fBif t(3) == 4\fP
.fi
.nf
\&  irb(main):007:1> \fBp :ok\fP
.fi
.nf
\&  irb(main):008:1> \fBend\fP
.fi
.nf
\&  :ok
.fi
.nf
\&  => :ok
.fi
.nf
\&  irb(main):009:0> \fBquit\fP
.fi
.nf
\&  %
.fi

.SH SEE ALSO
\fBruby\fP(1).

.SH REPORTING BUGS
Security vulnerabilities should be reported via an email to
<security@ruby-lang.org>
Reported problems will be published after being fixed.

And you can report other bugs and feature requests via the
Ruby Issue Tracking System (http://bugs.ruby-lang.org).
Do not report security vulnerabilities
via the system because it publishes the vulnerabilities immediately.
.SH AUTHORS
Written by Keiju ISHITSUKA.
